Energy Management Solution for Low Voltage Hybrid Vibration Converter

Several energy harvesters generating a low AC voltage up to millivolts have been developed in the recent years. Most of the consumers require a DC voltage source and only a few works were devoted to convert a low AC input voltage to a useful DC output. In this paper, an hybrid system energy management solution, combining electromagnetic and piezoelectric energy converters with low output voltage, is presented. The proposed topology consists of three main stages: An AC-DC rectifier for each source, a DC-DC converter and a maximum power point tracking (MPPT) aiming to maintain the maximum extracted power. The circuits are designed, simulated and evaluated. A maximum energy output level of 0.8 mJ from the hybrid system is reached. It is shown that the hybrid approach extracts more energy than each converter separately.